The central purpose of this project is the development of an inexpensive but highly responsive computer system for administering patient history questionnaires. The system organization is novel in that all interaction with the patient and all response analysis and branching decisions are made within the patient terminal, but storage of the questionnaire frames and logic is centralized and transmitted to the patient terminals by a one-way broadcast technique that does not require any communication from the patient terminal back to the central storage unit. Hence, the task of the central storage unit is unchanged by the addition of more terminals, and the system performance remains high regardless of the number of users. An initial system for use in the Washington University Psychiatry Clinic has been designed that uses a fixed-head disc for the central storage, cable television techniques with a bit rate of about 3 megabits per second per channel as the one-way communications medium, and inexpensive microprocessor (Motorola MC6800) as the core of the patient terminal. A system response time of about one tenth of a second is anticipated; the cost of terminals in small quantities is about $2600.